The present invention is directed generally to folding rules for measuring linear distances.
Folding rules, sometimes referred to as “carpenter's rules” or “wooden rules,” have been known for some time. Such rules have an advantage over conventional retractable tape measures in that the folding rules are generally much more rigid than the tape blades of the tape measures. This rigidity allows for the folding rules to be used more easily for many tasks, particularly for carpenters that work with cabinetry and brick masons.
Typically, folding rules are made with a plurality of segments that are joined together by pivot joints to form a collapsible chain. The segments are typically formed of wood, and joints are typically metallic. However, conventional wooden rules are sometimes viewed as being less than ideal for environments with electrical hazards, such as in the electrical utility industry, due to the potential of the wood to absorb water and become electrically conductive. Separately, synthetic folding rules have recently been introduced, such those made from fiberglass and the like, that allow for manufacturing cost reductions due to the “molding-in” of various joint elements. While such synthetic folding rules have some advantages, they are disfavored by many consumers for various reasons.
Thus, while a number of folding rule designs exist, none have proven entirely satisfactory. As such, there remains a need for alternative folding rule designs.